Anadarko's stock surged more than 16 percent late last week after the settlement was announced to peak at a new high of $103.50 a share. It has since come down on Monday to level out at about $97.50 near closing time, but that still represents a huge jump from the $78 to $85 range Anadarko was trading at most of this year.

"It's the first time in the last five or six years they haven't had some kind of legal overhang," Coleman said. "It makes it more investable for a lot of folks now."

The Woodlands-based energy company also recently found not culpable in the 2010 Deepwater Horizon disaster. Coleman said that Anadarko largely getting two big legal issues behind it starts to renew rumors of the energy exploration and production company being sold to supermajors, such as Irving-based Exxon Mobil Corp. (NYSE: XOM).

"It's hard to sell it when you have an unknown liability. That's all gone," Coleman said.

But that does not mean a major sale is upcoming or even likely, Coleman said. There are plenty of questions regarding the uncertainty of oil prices hovering around $100 a barrel and few companies are capable of buying a $50 billion energy giant like Anadarko, he added.

"At some point down the road, it's possible they split the company or sell," Coleman said.

He said it would likely represent the biggest deal since Exxon bought XTO Energy Inc. more than four years ago.

Anadarko, based in The Woodlands, is resolving a legal battle waged against its subsidiary, Kerr-McGee Corp., over billions of dollars related to environmental cleanup and health concerns that occurred before Anadarko acquired the company in 2006.

The lawsuit was filed by Tronox Inc., which spun off from Kerr-McGee in 2005 before Anadarko's acquisition. Tronox later filed for bankruptcy and then filed the suit claiming Kerr-McGee should be held liable for alleged environmental damage incurred before the spinoff. The suit sought $25 billion to clean up more than 2,000 sites across the U.S.

Anadarko’s $5.15 billion settlement comes less than a month after a federal judge said Anadarko was not culpable in the 2010 Deepwater Horizon tragedy in which BP PLC (NYSE: BP) was the primary operator in the Gulf Coast. Anadarko had already agreed to pay BP $4 billion to help with cleanup costs for its share in the Gulf well.

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